1. Field of the Invention
The invention relates to a measuring device having a housing and having a central measuring opening that passes through the housing in a straight line, and having a measuring coil that is disposed in the housing and encloses the measuring opening.
2. Description of the Related Art
Such arrangements are commercially available as ring coils, for example. They serve for detecting changes in cross-section of a work piece that runs axially through the measuring opening, for example, by a change in inductivity or, alternatively, by eddy current measurements, for example, in that two measuring coils, one for inducting the eddy currents and one for detecting the eddy currents, are installed accordingly. U.S. Pat. No. 4,862,079 also discloses a corresponding arrangement, wherein here, the measuring coil appears to be mounted in the housing. An arrangement having movable measuring coils that support themselves, which are carried, by two laterally disposed bolts that allow mobility, is disclosed, by U.S. Pat. No. 5,638,000.